Diff oil change

[lew l]

Just finished a differential oil change. I used Castrol 80 weight synthitic (MTX ). In the drained oil I noticed a gold like sheen in the oil. In motor oil I know this is bad and means the bearings are going. Same for the differential--no??
            Lew

[timmer]

What I would do is go for a nice ride on the bike and then upon returning drain the oil again. The oil would be at normal riding temperature. Might do this 2 or 3 times, the diff doesn't take much oil so it would be cheap and easy to do. This should flush out the housing really good. Then I would refill and put 500 to 1,000 miles on and then check it to see what condition the oil appears to be in. I don't think you have a problem, but for piece of mind the above might be the ticket. Problems with the rear wheel are generally with the wheel bearings going out and the splines becoming shot because of little or no maintenance being preformed. The splines should be checked every 10K for proper lubrication with moly paste. There are write ups on the forum that explain what you need and how to do it etc....


timmer

[salty]

This is not a very timely post. But I agree with timmer, flush by dilution and change the final drive fluid frequently. I own alot of bikes with shaft drives and they are pretty much bullet proof if you maintain them. Of course, is there any other kind of bike than a HONDA?

[ossvalk]

have you washed the bike using high pressure hose.

I would guess that it may be a drop of water in that oil that caused the sheen

It may be possible that the vent cap could allow a smigeon of water in if sprayed directly onto the cap

I wouldnt worry too much

In mine is severe duly 75-90 amsoil  I change it every few years but the company says it will last many times that.  For the price drain again and then inspect the oil, should be fine

Next time you do the drive shaft maintenance check to see the 2 drain holes for the upper end are clear also

[NITRO]

And for further peace of mind, I've never heard of final drive bearings failing. The splines and pinion cup, however, are a different story.

[cookiedough]

I just got done finally today changing oil and for the first time my rear gearcase oil 75w-90 amsoil in my bike.  Pretty easy to do although running a hose up and around the exhaust even with my hardside bags off  and pumping out of the bottle at the same time was a pain and had the misses hold the hosing so the tubing would stay in the opening.  I probably put in 5.5 ounces reqd. 5.1 ounces (a tad too much???) since standing the bike level off the side stand for a few minutes had very little running out of the top hole.   I doubt 5.5 or even 6 ounces max. would do any damage to the rear gearcasing since only needed 5.1 ounces.  I measured the old oil in a glass measuring cup that came out and it was about 4.9 ounces just shy of 5.1 ounces needed.  But, boy oh boy, the old oil was a chocolate milk color with the bottom drain plug having about 1/4" of built up grease/gunk on the bottom tip of the plug that I wipped off.  Long overdue seeing as how bike is 11 years old now and probably never done although only 23K on bike. 

Sad, but going to put it up this weekend since snow will be here next week.  Took it out for 1 last spin around my one horse town.  Now just have to put summer crap away in the garage to find a place to put the bike.  Nothing like ONLY having a std. 20x24 garage when I really need a 4-5 car garage. 

I hope all had a happy turkey day and found good deals on black friday although the crowds were nuts yet again as always just to save a few hundred bucks.